1. Field of the Invention
This invention relates to an engine speed control apparatus for an outboard motor, particularly to an apparatus for controlling a speed of an internal combustion engine of an outboard motor by opening/closing a throttle valve by an actuator.
2. Description of the Related Art
Conventionally, there is proposed an engine speed control apparatus having an actuator connected to a throttle valve of an internal combustion engine installed in an outboard motor and a throttle lever installed on a boat. Based on a manipulation amount of the throttle lever, the apparatus controls the operation of the actuator to open/close the throttle valve, thereby controlling the engine speed.
In recent years, a configuration is given in which, in addition to the above-mentioned throttle lever, a switch is provided on the boat and based on an output of the switch, the operation of the actuator is controlled, so that the operator can easily regulate the engine speed only by manipulating the switch, as taught, for example, by Japanese Laid-Open Patent Application No. 2005-335449 (paragraphs 0030, 0031, 0051, FIGS. 2(B), 10(A), etc.).